I've long wondered why Puerto Ricans don't count as "white." Since they cannot be the descendants of the actual original inhabitants (who were exterminated by the Honorary Indigenous Spaniards) I assumed that the only thing keeping them from being white was the Spanish language (you know, the indigenous American language that all Indians spoke before the "rednecks" came along).
To add more confusion is the fact that 79% of the population of PR is identified as "white" per the US Census. The reason for this is that the US Census does not have a multiracial category, and those on PR who are 70% white/30% black check "white" as their racial category. It also goes back to the fact that, when PR became a US territory, PRs were encouraged to choose "white" due to concerns about Jim Crow/Eugenics amongst mainland politicians.
In truth, now backed up by genetic studies, the majority of Puerto Ricans are of mixed European and African ancestry, with some Taino admixture amongst the jibaros in the mountains. Amongst themselves, PRs use terms such as "trigueno" (high yellow) or "jabao" ("off-white") rather than the simple white/black categories we have on the US. If we went by face value, about 35-40% of the population of PR could at least pass for white/European, as the majority of the folks you'll meet in PR have noticeable African features.